A solar panel (or solar cell panel) is generally adapted to collect solar energy and transform the collected solar energy to electrical energy. When the solar panel is sheltered by a cloud or some leaves and the like to produce a shadow on the solar panel, it will cause a heat plate effect on the sheltered cell pieces and thus result in over-burning of the cell pieces. A diode in the junction box acts as a bypass when producing the heat plate effect so as to prevent the cell pieces from being over-burnt.
In the prior art, the photovoltaic junction box is directly mounted on a solar panel and is electrically connected with a bus bar of the solar panel. The photovoltaic junction box is provided with a plurality of conductive terminals and a plurality of diodes electrically connected to the conduction terminals, wherein an anode and a cathode of each diode are soldered on a pair of adjacent conduction terminals, respectively. In operation, the diode will produce heat, and then the produced heat will be transferred to the conduction terminals.
In the prior art, opposite edges of adjacent conduction terminals exhibit lines parallel to each other, and the anode and the cathode of the diode are soldered on areas in the vicinity of the edges of the adjacent conduction terminals, respectively. With regard to the current design of the conduction terminals, the diode welded on the conduction terminal has a heat conduction angle, which can only be equal or less than 180 degrees. In this way, the heat conduction efficiency of the conduction terminal will be reduced, and the heat produced by the diodes cannot dissipate to the conduction terminals in time to avoid deterioration or damage to the diode, deteriorating or damaging the diode over time and thus limiting a current-carrying capacity of the solar junction box.